About 10 kilometers to the south and east is the Montes Haemus range that forms the edge of the Serenitatis basin. This crater has a relatively high albedo, with a sharp-edged rim that displays little appearance of wear. There is a small rise at the midpoint. Recent deposits of highland material have been observed within the crater interior. This material was observed to be orange by Apollo 17 astronauts during their LMP ascent.[2]
To the northwest is a rille system designated the Rimae Sulpicius Gallus. These extend to the northwest for a distance of about 90 kilometers, curving and branching out to follow the edge of the mare.
Satellite craters
By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Sulpicius Gallus.
Menzel, D. H.; Minnaert, M.; Levin, B.; Dollfus, A.; Bell, B. (1971). "Report on Lunar Nomenclature by the Working Group of Commission 17 of the IAU". Space Science Reviews. 12 (2): 136–186. Bibcode:1971SSRv...12..136M. doi:10.1007/BF00171763. S2CID122125855.